This abduction sparked a war between the two powers. Gwythr pursued Gwyn to the ends of the earth to reclaim his bride, leading to a catastrophic battle that threatened to destroy the balance of the world.
: Gwyn and Gwythr must fight every May Day (Calan Mai). gwythr
While the duel is his most famous role, Gwythr also appears as a loyal ally to Arthur. In the quest for Olwen, he assists Culhwch in completing several "impossible" tasks. One notable episode highlights his compassion: Gwythr rescues an anthill from a forest fire. In gratitude, the ants assist him in a later task. This abduction sparked a war between the two powers